Originally Posted by richarddd

"As you can see, MasterCard’s exchange rate is better in all instances, except with the Japanese Yen, where Visa is slightly better.

Rumor has it that the reason for this discrepancy is as follows:

- Visa guarantees the exchange rate the day you make the purchase, but has a built in cushion since the transaction typically only posts a couple of days later, so exchange rates could change, meaning there’s some risk for Visa

- MasterCard charges the exchange rate the day the transaction posts (often a couple of days after the transaction), so since they’re charging whatever the rate is, the cushion is much smaller"

http://onemileatatime.boardingarea.c...exchange-rate/